I'm not a professional HVAC guy, but even so I've performed lots of my own AC work on both household and automotive applications. I honestly had low expectations for the build quality of this scale, just based on the brand, but boy was I proven wrong. I expected lots of plastic, but instead it's all steel with a durable rubberized mat on top. The controller is plastic, but doesn't feel the least bit cheap. It measures very accurately so far as I can tell. I tested it many times over with different objects on different parts of the scale, and it always returned the same weight no matter what with infinite repeatability. I even stood on it and weighed myself, and it came back with the same numbers no matter how I shifted my weight. It really is a far cry from the cheapo shipping scale that I used to use for weighing in refrigerant bottles before I had this. Even the case that this comes in feels very high quality just in terms of the latches and the molding. I'm not sure what the $250-300 scales offer that this one doesn't but I can't imagine it's much. If you're just doing small DIY sized refrigerant bottles and nothing else, I suggest the 110lb capacity scale for that little extra bit of accuracy. I only chose the 220lb model because for me this also serves double-duty as a higher capacity shipping scale.